The alkenylation of aromatic hydrocarbons by dienes has been described repeatedly in the literature (inter alia: G. O. Olah, Friedel-Crafts and Related Reactions, vol. II/1). This preparation takes place using homogeneous and heterogeneous acidic catalysts, producing predominantly alkenyl and/or dialkenyl derivatives of aromatic hydrocarbons of the formulae ##STR3## wherein Ar is an aryl residue,
the residues R, independently of one another, are hydrogen or alkyl, and PA1 n and m each are 1 or 2. PA1 3.2 R.sup.1 through R.sup.16 are, independently of one another, PA1 3.2.1 straight-chain or branched, saturated or unsaturated, aliphatic or cycloaliphatic hydrocarbon residues of 1-20 carbon atoms, optionally substituted by halogen atoms,
Such products heretofore were only of relatively low interest and frequently had the character of undesirable by-products. Due to their high proportion of trans-double bonds, they possessed poor air-drying properties and furthermore were relatively readily volatile. Longer-chain telomers (n&gt;2) are normally produced only to a minor extent.
Products having longer side chains can be obtained by following the methods of German Pat. No. 1,137,727 and German Pat. No. 1,170,932. They, too, contain primarily trans-double bonds and, in all cases, a considerable proportion of undesirable, readily volatile monoalkenylation products (see also H. Weber and B. Schleimer, "Brennstoff-Chemie" [Fuel Chemistry] 49:329 et seq. [1968]). They have been proposed for use in modification of elastomeric and thermoplastic synthetic resins, of lubricants and, after hydrogenation, of detergent raw materials.
Using catalysts from Cr(III) halides and alkyl aluminum halides according to the process of U.S. Pat. No. 3,373,216, products are obtained, having a trans-content which has been reduced (35-80%). However, they contain only minor proportions of incorporated aromatics.
Japanese Laid-Open Application No. 49-32985 describes a process for the preparation of polymers containing aromatic hydrocarbons on a polydiene chain (incorporation takes place probably statistically along the polydiene chain). A nickel catalyst modified by halogen compounds of nobornene is used. This method produces products containing, for example, per 1 mole of diene, 0.5 mole of aromatics and in some cases more than 70% of cis-1,4-double bonds.
German patent application No. P 28 48 804.2, corresponding to U.S. patent application Ser. No. 091,909, filed on Nov. 6, 1979, whose disclosures are incorporated by reference herein, relates to a process also producing reaction products of conjugated diolefins and aromatic hydrocarbons having a high percentage proportion of cis-1,4-double bonds and, as can be seen from its examples, only a minor portion (.ltoreq.1%) of 1,2-double bonds. In this process, not yet pertaining to the state of the art, conjugated diolefins are polymerized in an aromatic hydrocarbon using a catalyst consisting of a nickel compound soluble in the aromatic hydrocarbon, a halogen-containing organoaluminum compound, a selected modifier, and, optionally, water.
In U.S. Pat. Nos. 3,983,183 and 3,966,697, a P modified Co catalyst is disclosed as one component of a catalyst system used to polymerize conjugated dienes to form vinyl-containing polymers having low 1,4-trans-double bond contents.